1. Field of Invention
The present invention relates to portable structures and more particularly to a an easily erected, temporary shelter designed to envelope a wellhead and the immediate surrounding area for protecting workers, the wellhead and the well from the elements such as thunderstorms, tropical storms, extreme cold and the like, and providing an optimal environment for welding, heat treatment and other processes.
The present invention also discloses a new and unique means of overhead protection for its occupants as well as self contained ventilation means for the removal of any toxic fumes or vapors associated with welding and related processes.
The present invention further teaches a new and unique framing system comprising telescoping support members attached directly to the wellhead to provide ample room in the shelter; the configuration and design of the shelter is such that it is able to withstand the harsh weather associated with the offshore drilling environment, yet is lightweight, sturdy and easily assembled and disassembled. Alternative means of support are also disclosed.
While the present invention is taught as being used primarily with wellheads, it is noted that this invention may be used in an unlimited variety of configurations and applications, including but not limited to construction relating to buildings, bridges and other large structures and the fabrication of offshore support structures, process piping, production platforms, and the like.
2. Prior Art & General Background
Oil and gas drilling, both on-shore and offshore, has traditionally been a difficult and expensive undertaking. Merely reaching the oil, gas or other resource, many thousands of feet in the ground, is acknowledged as a tremendous feat of engineering. But sometimes equally difficult is coping with the often severe weather associated with the immediate drilling environment on the well bay area of the platform drilling rig, or in the case of a jack-up rig, the "texas deck," during drilling operations and wellhead installations.
It appears that much of the oil, gas and other minerals to be found happen to be in some of the lesser hospitable environments: the arctic, the desert, offshore and the like. High winds, tropical storms, low temperatures, and moisture in some form or another is excessively prominent in many of these areas. The offshore is particularly inhospitable to drilling operations, where tropical storms, gale force winds and very low temperatures are common, as is heavy moisture in the form of rain, snow, hail, sea breeze, etc.
One particular operation in oil field drilling which is particularly vulnerable to harsh and severe weather conditions is the pre- and post-heat treatment of the wellhead, casing and conductor pipe prior to, during, and upon completion of the welding of the wellhead and casing.
During welding operations, the wellhead and casing must be pre-heated some 250 to 1,150 plus degrees fahrenheit in order to provide for a uniform preheated welding surface to insure a high quality weld. High winds, rain, and intense cold tend to greatly hamper the heating and welding processes to a point of making it impossible much of the time, as the heat is dissipated as fast as it is produced.
In addition, the wellhead and casing must be kept free from winds, rain and moisture during the pre-heating and welding process, as the variations in temperature associated with the rain and/or shifting winds coming into contact with the heat affected zones of the wellhead and casing or otherwise undesirable welds such as crooked welds, leaking welds and the like.
Heretofore, the oil and gas industry has not provided a shelter specifically designed to facilitate an optimal environment during tropical storms and the like for the pre-heating and welding of the wellhead, casing and conductor pipe on the well bay floor of a production platform or the "texas deck" of a jack up rig. In the past, many of the problems associated with providing wellhead shelters in order to increase worker productivity and efficiency in the preheating and welding processes during hostile weather such as thunderstorms, tropical storms and the like were due to the nature of the preheating and welding process itself, which could generate life threatening, toxic fumes and vapors. Closed shelters were thus not advantageous, as the fumes and vapors would not be dissipated adequately, endangering any worker in the shelter.
Further, the hostile weather conditions themselves would make erecting the structure difficult; this is especially true for one designed to withstand high winds and heavy rains, thereby normally requiring heavy and cumbersome support structures. Further, heretofore the industry has failed to design a portable structure which would adequately shelter the worker, the wellhead and the well, while providing an environment having space conducive to the preheating and welding process during inclement weather conditions.
At present, with no structure to shelter the wellhead and welder from any and all adverse elements during heating and welding, there is no other alternative but to shut the rig down at a cost of many tens of thousands of dollars for every hour, while waiting for weather conditions to improve. The present invention enables the rig to successfully preheat and weld the wellhead non-stop during thunderstorms, tropical storms, and the like, or in any environment or harsh weather condition, thus saving the rig thousands of dollars of lost rig time and loss of production.
The prior art does appear to anticipate basic tent-like shelter structures for protection of horizontal, below ground transport pipeline welders and the like, but does not anticipate the present invention in its preferred form, which provides a new and unique device and method for sheltering a wellhead and its occupants during heating and welding in inclement weather (tropical storms, etc.) and teaching active ventilation means, overhead protection, heavy duty, sturdy but light weight construction, and easily assembled and disassembled.
A list of prior patents which may be of interest are cited below:
______________________________________ Patent No. Patentee(s) Issue Date ______________________________________ 1,834,655 C. E. Shaw 12/01/1931 2,196,704 W. C. Markle 11/03/1938 2,235,274 Hampton 11/30/1943 2,528,721 Brockman et al 11/07/1950 2,804,951 Kolt 09/03/1957 3,198,285 Nerlich 08/03/1965 3,452,764 Bell 07/01/1969 3,529,427 Titman 09/22/1970 3,783,906 Matherne 01/08/1974 ______________________________________
U.S. Pat. No. 2,196,704 entitled "Windbreak for Oil Derricks" teaches a single wall canvas windbreak to be incorporated into the top platform structure of an oil derrick to protect any workers on the top platform from exposure. This shelter comprises essentially a wind screen designed to prevent its occupants from being blown off the upper deck and is clearly distinguishable from the present invention.
U.S. Pat. No. 3,783,906 entitled "Apparatus for Welding Vertical Members during Inclimate Weather" teaches an umbrella-like canopy, which may be mounted around the periphery of stacked drive pipe or conductor pipe, to prevent rain from falling upon the pipe during welding.
It is noted that this patent only teaches an umbrella-like "roof" structure of canvas and not "walls", and apparently is more of a sun and very light rain shelter. The patent apparently does not contemplate utilization of the structure during tropical storms and the like, which includes driving rain or high winds, as the design of the patent would not adequately protect the pipe and the welder from the rain blown under the structure by the wind.
Further, utilization of the patent in high winds would apparently cause the structure to reverse, much as an umbrella would when the wind catches it from underneath. In addition, the structure does not contemplate overhead protection means, as the fabric would certainly not provide adequate protection for overhead falling objects or corrosive liquids.
Additionally, it is apparent that the above patent does not contemplate a light weight but heavy duty easily fabricated structure for providing a totally controlled environment, insulated from the outside environment for more efficient, controlled preheating with active ventilation means and overhead protection like the present invention.
U.S. Pat. No. 3,452,764 entitled "Pipeline Welder's Tent" teaches a tent structure adapted to providing a working environment for welders fabricating or repairing horizontal, underground transport pipelines. The patent teaches the incorporation of passage holes in the side walls for pipeline, and the tent-like structure is to provide an "enclosure of the workman himself within an environment which could enhance his working effectiveness".
Like the other prior art, this patent is clearly distinguishable from the present invention. The above patent is merely a standard tent design adapted to receive pipe through its walls to protect the welders from the elements. This patent does not protect the welder and the weld from excessive driving rains from overhead and on the side passage holes of the test while welding, and this patent fails to incorporate adequate protection from pouring rains which might fall through the tent, as well as failing to provide adequate ventilation means and this failure could result in worker exposure to excessive toxic fumes, thereby causing injury and perhaps even death.
Thus, based upon the above and foregoing, one can ascertain that there clearly exists a need for a portable, easily erected wellhead protective shelter, which would allow for more efficient heating and welding of wellheads and casing on the well deck of the production platform below the drilling rig and the "texas deck" of a jack up rig which would provide means of maintaining a desirable temperature therein while allowing active ventilation of toxic fumes and vapors under virtually all weather conditions, and provide overhead protection as well.
3. General, Summary Discussion of the Invention
The present invention overcomes these prior art problems by providing a portable, on site wellhead and welder protection system, which is highly reliable, relatively economical and very cost effective.
The preferred embodiment of the present invention provides a structure which is comprised essentially of three components the overhead shelter/ventilation means, side walls, and adjustable support means. These component parts are designed to provide a heavy duty, sturdy but easily fabricated shelter in a manner which allows for the device to be relatively light in weight and transportable in a single, relatively compact storage case.
The preferred embodiment of the present invention teaches a unique, adjustable support means affixed directly to the wellhead of the drilling apparatus. This embodiment is designed to be used for wellhead heating and/or welding while on the well bay deck of the drilling rig or platform, protecting the worker from the outside environment, whether it be tropical storms, excessive cold, rain, winds, or overhead falling objects and liquids from the rig itself.
An alternative embodiment of the present invention contemplates a similar overall design as the preferred embodiment, but having support means for use in conjunction with the "texas deck", a somewhat unstable deck utilized in conjunction with jack-up drilling rigs, generally supported in mid-air by cables under the rig itself. This deck generally has a grating floor suspending a significant height above the water, having an opening in the center which allows for the drive or conductor pipe and wellhead to pass into the drill bore.
A problem associated with working on the texas deck relates to the instability and danger associated with the design of the deck itself. As mentioned above, the deck is generally suspended by support cables from the upper deck of the drilling rig. High winds and rain causing the texas deck and the conductor or drive pipe which is supporting the wellhead to rock to and fro, providing a base which is not only almost impossible to work on, but also highly dangerous.
Adding to the danger of this situation is the fact that the texas deck and conductor or drive pipe tend to rock in opposite directions or rhythms, the texas deck influenced by the wind and the drive or conductor pipe influenced by rough seas. The high winds and rough seas in combination thus cause the texas deck and conductor pipe to oscillate at two separate frequencies clashing at their union on the texas deck.
The alternative design of the present invention for use in conjunction with a texas deck incorporates means to stabilize the immediate environment of the wellhead and welder protector in the form of a portably attached floor area directly connected to the wellhead and base plate of the wellhead, suspending the wellhead and welder protection device with its own floor above the texas deck, thereby freeing the welder from the rocking texas deck and wellhead, and providing an environment totally isolated from all inclement weather, with means of ventilating toxic fumes and over head protection means.
The preferred embodiment of the present invention contemplates an overhead support structure of aluminum or other light weight material, sectioned in two parts for transportation purposes, but which is easily joined to form one sturdy, somewhat planar surface. The over head protection structure is designed to prevent overhead falling objects from hitting, injuring or killing the workers. The overhead protection structure is also designed to prevent water and other liquids from flowing or otherwise falling into the environment of the wellhead, and thus incorporates a gasket between the joined halves in order to provide a liquid resistant seal.
The telescoping support members are threadingly attached to the overhead support structure and are able to be affixed in a variety of configurations to fit the different configuration and size wellheads used via adjustable mounting means incorporated into the overhead support.
The overhead support structure also includes active ventilation means for ventilating excess heat and/or toxic fumes which form during welding operations. The ventilation mean in the preferred embodiment is in the form of a thermostatically controlled electric turbine mounted on the overhead support structure of the present system. Other devices for ventilation, including but not limited to wind driven turbines and the like, may be used; the choice of turbine and/or other types of nonmovement ventilators is dependent upon the climate and needs associated with the particular operations involved.
The sidewall of the present invention is fabricated of a heavy duty, water and fireproof fabric, and includes means for easy attachment to the overhead support, adjustable ventilation ports, vinyl windows, passage means, and means for attachment to the well deck, or, in the form of a texas deck, means for attachment around the base of the wellhead and casing.
The sidewall is specifically designed to be windproof and have thermal insulating characteristics in order to increase the efficiency of pre- and post-heating operations of the wellhead and casing or conductor pipe and provide for an optimal environment for welding and other operations associated with but not limited to the fabrication, maintenance, and support of the well and wellhead.
The present invention is designed to be transported with the welding team to the site, erected and utilized, taken down and repacked for another use elsewhere. The present structure is thus configured to provide for a wellhead and welder protection, which includes maximum ease of fabrication, with all parts secured and adjusted in a manner which provides for maximum time savings yet produces a highly stable structure.
The structure, once erected, provides a controlled environment which provides for much more efficient heating of the wellhead and casing in adverse weather, such as tropical storms and the like, and allows for welding under weather conditions such as thunderstorms, tropical storms, etc., which would normally prohibit such activities.
It is thus an object of the present invention to provide a wellhead and welder protector which includes active ventilation means and overhead protection means.
It is also an object of the present invention to provide a wellhead and welder protector which is relatively light in weight, easily transportable and quickly erected, yet heavy duty and able to withstand harsh weather such as thunderstorms, tropical storms and the like.
It is a further object of the present invention to provide a wellhead and welder protector which is directly attached to the wellhead, in an adjustable manner so as to provide maximum efficiency with regard to the amount of sheltered area.
It is a still further object of the present invention to provide for a wellhead and welder protector having active ventilation means designed specifically for ventilating toxic fumes associated with welding processes and the like.
It is another object of the present invention to provide a wellhead and welder protector having means to provide a stable working environment for use in conjunction with but not limited to wellheads on a texas deck.
It is still another object of the present invention to provide a wellhead and welder protector having means of providing a controlled environment specifically tailored for the increased efficiency of pre- and post-heating operations with regard to the preparations of the wellhead, casing and/or conductor pipe of the well.